Python Errors and Built-in Python Exceptions

In this article, we will discuss about python errors, types of errors and python in-built exception with the help of examples.

Python Errors

Errors refers to the mistakes which we make while writing a program and which stops the execution of that particular program. If a unhandled error occurs in python, then it simultaneously terminates the program.

Types of Python Errors

In python programming language, you will able to see two types of errors which are discussed as follows;

1. Syntax Errors

In python, syntax error refers to those errors which is thrown when a proper structure or syntax of a language is not followed by the programmers. Syntax Error is also called Parsing Error.

# initialize the amount variable 
digits = 100
# check that You are eligible to
if(digits>29) 
    print("Hence Verified!!") 

Output

File "<string>", line 4
    if(digits>29) 
                 ^
SyntaxError: invalid syntax

2. Logistic Errors (Exceptions)

Logistic Errors refers to those errors which occurs at the runtime after passing the syntax. These errors also known as Exceptions. When the normal flow of a program change due to internal events, it raises an exception. An exception object is created when these logical type errors occur in a program and python creates a traceback to that error if it is not handled properly. For example - The exception may occur when when we try to import non-existing module i.e., or when we try to open a non-existing file i.e., .

Example 1: Got an error when you perform division with 0

# initialize the amount variable 
result = 100
# perform division with 0 
x = result / 0
print(x)

Output

Traceback (most recent call last):
  File "<string>", line 4, in <module>
ZeroDivisionError: division by zero

Example 2: Got an error when indentation is not correct.

if(a<3): 
print("Foobar")

Output

File "<string>", line 2
    print("Foobar")
    ^
IndentationError: expected an indented block

Built-in Python Exceptions

Here is the list of common exception which occurs in the python programming language;

Exception	Cause of Error
ValueError	It occurs when a function gets correct argument type but improper value.
TypeError	It occurs when a function is applied to an object of incorrect type.
NameError	It occurs when the variable is not found in global and local scope.
ZeroDivisionError	It occurs when the second operation of a division is zero.
IndexError	When the index of a sequence is out of range, it occurs.
SyntaxError	It occurs when the syntax error is encountered.
AttributeError	It occurs when the attribute assignment fails.
EOFError	It occurs when the input function reach the end-of-file condition.
RuntimeError	It occurs when an error doesn't fall under other category.
IndentationError	It is raised by incorrect indentation.
AssertionError	It occurs when the assert statement fails.
KeyError	It occurs when the key is not found in the dictionary.
MemoryError	It occurs when an operation runs out of memory.
FloatingPointError	When the floating point operation fails, it occur.
SystemExit	It is raised by the sys.exit() function.
OSError	It occurs when the system related error is caused by the system operation.
NotImplementedError	It is raised by the abstract methods.
OverflowError	It occurs when the arithmetic operation's result is too large to be represented.
UnicodeError	It is raised when unicode-related decoding or encoding error is occurred.
UnicodeTranslateError	It is raised when unicode-related error occurred during translating.
UnboundLocalError	It occurs when a reference is made to a local variable in function but no value has been assigned to that variable.
ReferenceError	It occurs when to access a garbage collected referent, a weak reference proxy is used.
UnicodeDecodeError	It occurs when unicode-related error raised during decoding.
UnicodeEncodeError	It occurs when unicode-related error raised during encoding.
GeneratorExit	It occurs when the close() method of generator is called.
ImportError	It occurs when the import module is not found.
KeyboardInterrupt	It occurs when the interrupt key is hit by the user.
StopIteration	It occurs when the next() function indicates that there is nothing to be returned by the iterator.
TabError	It occurs when indentation consists of inconsistent tabs and spaces.
SystemError	It occurs when the internal error is detected by the interpreter.

Conclusion 

Above we have discussed about python errors, types of errors and python in-built exception with the help of examples. Errors refers to the mistakes which we make while writing a program and which stops the execution of that particular program. In python programming language, you will able to see two types of errors i.e., syntax errors and logistic error or exceptions.